Zeolite can be used for adsorbents, desiccants, separating agents, catalysts, catalyst carriers, detergent aids, ion exchangers, waste water treatment agents, fertilizers, food additives, cosmetic additives and the like, and, in particular, is useful in gas separation applications.
A GIS-type zeolite is disclosed in each of Patent Literatures 1 to 2 and Non-Patent Literatures 1 to 3. Such a GIS-type zeolite here has a GIS structure in codes for directing zeolite structures specified by the International Zeolite Association (IZA).
A GIS-type zeolite is a zeolite having a pore constituted by an oxygen 8-membered ring. Patent Literature 1 describes synthesis of a GIS-type zeolite for effective use of slag of coal burnt ash, and Patent Literature 2 describes an enhancement in thermal conductivity by formation of a zeolite film (GIS-type zeolite) on the surface of an aluminum plate. Non-Patent Literatures 1 and 2 each disclose a GIS-type zeolite of silica/alumina, and adsorption of carbon dioxide is not almost found in all of such disclosures. Non-Patent Literature 3 discloses a GIS-type zeolite of silicoaluminophosphate containing phosphoric acid, and reported that not only adsorption of carbon dioxide, but also adsorption of oxygen, nitrogen and methane were observed.